Tag: Hymenoptera

New ant species from Borneo explodes to defend its colony

Minor worker of the new species in a defensive pose.

Amongst the countless fascinating plants and animals inhabiting the tropical rainforests of Southeast Asia, there are the spectacular “exploding ants”, a group of arboreal, canopy dwelling ants nicknamed for their unique defensive behaviour.

When threatened by other insects, minor workers can actively rupture their body wall. Apart from leading to the ants’ imminent death, the “explosion” releases a sticky, toxic liquid from their enlarged glands, in order to either kill or hold off the enemy.

Three 'exploding' ants of the new species grasping onto a weaver ant. — Three ‘exploding’ ants of the new species grasping onto a weaver ant.

Curiously enough, while these ants’ peculiar behaviour was first mentioned in distant 1916, no new species have been formally described since 1935, due to insufficient evidence. Instead, scientists used to simply refer to them as the members of a remarkable species group – Colobopsis cylindrica, better known as “the exploding ants”.

That was until an interdisciplinary research team from Austria, Thailand and Brunei came together led by their shared fascination with these insects and their extraordinary mechanism of self-sacrifice (also called autothysis) in 2014. Thus, entomologists, botanists, microbiologists, and chemists from the Natural History Museum Vienna, Technical University Vienna, IFA Tulln and Universiti Brunei Darussalam together identified roughly 15 separate species of exploding ants, with one of them now described as new to science in the open access journal ZooKeys.

Aptly named Colobopsis explodens, previously nicknamed “Yellow Goo” for its bright yellow gland secretion, the new species has been picked as the model species of the group, after the scientists deemed it to be “particularly prone to self-sacrifice when threatened by enemy arthropods, as well as intruding researchers”.

The new species grasping onto a larger unidentified 'exploding' ant. — The new species grasping onto a larger unidentified ‘exploding’ ant.

Being a “model species” means that the ant will serve as an important navigation point in future studies on exploding ants. Publications regarding their behaviour, chemical profile, microbiology, anatomy and evolution are currently in preparation, say the authors. In addition, there are several more new species expected to be described in the near future.

While minor workers exhibit the ability to “explode”, the other castes have specialities of their own. For example, major workers (also called “doorkeepers”) have big, plug-shaped heads used to physically barricade the nest entrances against intruders.

Major worker of the new species ('doorkeeper') with characteristically enlarged head. — Major worker of the new species (‘doorkeeper’) with characteristically enlarged head.

During a sampling trip to Brunei in 2015, project members Alexey Kopchinskiy and Alice Laciny even managed to observe queens and males on a mating flight. They sampled the first males of these ants ever to be seen.

The same expedition was used to record the ants’ activity schedule and conduct the first experiments on food preferences and exploding behaviour.

While the exploding ants play a dominant role in rainforests, their biology still holds a number of secrets. The observations and experiments conducted on the newly described species have laid important groundwork for future research that will uncover even more details about these enigmatic explosive insects.

Watch this video to observe the behaviour of the exploding ants in various settings.

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Learn more about the ‘Exploding ants’ project at: http://explodingants.com/

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Original source:

Laciny A, Zettel H, Kopchinskiy A, Pretzer C, Pal A, Salim KA, Rahimi MJ, Hoenigsberger M, Lim L, Jaitrong W, Druzhinina IS (2018) Colobopsis explodens sp. n., model species for studies on “exploding ants” (Hymenoptera, Formicidae), with biological notes and first illustrations of males of the Colobopsis cylindrica group. ZooKeys 751: 1-40. https://doi.org/10.3897/zookeys.751.22661

A new hope: One of North America’s rarest bees has its known range greatly expanded

The Macropis Cuckoo Bee is one of the rarest bees in North America, partly because of its specialized ecological associations. It is a nest parasite of oil-collecting bees of the genus Macropis which, in turn, are dependent on oil-producing flowers of the genus Lysimachia.

In fact, the cuckoo bee – which much like its feather-bearing counterpart does not build a nest of its own, but lays its eggs in those of other species instead – is so rare that it was thought to have gone extinct until it was collected in Nova Scotia, Canada, in the early 2000s. As a result, the Macropis Cuckoo Bee was brought to the attention of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

Recently, an individual reported from Alberta, Canada, brought new hope for the survival of the species. In addition to previously collected specimens from Ontario, this record greatly expands the known range of the cuckoo.

Scientists Dr Cory S Sheffield, Royal Saskatchewan Museum, Canada, who was the one to rediscover the “extinct” species in Nova Scotia, and Jennifer Heron, British Columbia Ministry of Environment & Climate Change Strategy, present their new data, and discuss the conservation status of this species in their paper, published in the open access journal Biodiversity Data Journal.

“This species has a very interesting biology,” they say, “being a nest parasite – or cuckoo – of another group of bees that in turn have very specialized dietary needs.”

The hosts, bees of the genus Macropis (which themselves are quite rare) are entirely dependent on plants of the primrose genus Lysimachia. Moreover, they only go after those Lysimachia species whose flowers produce oil droplets, which the insects collect and feed to their larvae. Thus, Macropis bees require these oil-producing flowers to exist just like Macropis cuckoo bees need their hosts and their nests. Curiously, this reliance, as suggested by previous studies on related European species, has made the female cuckoos develop the ability to find their host’s nests by the smell of the floral oils.

“This level of co-dependence between flower, bee, and cuckoo bee, makes for a very tenuous existence, especially for the cuckoo,” the authors comment. “The recent specimen from Alberta lets us know that the species is still out there, and is more widespread than we thought.”

In conclusion, the authors suggest that continuing to monitor for populations of rare bees, and documenting historic records, are crucial for conservation status assessments of at-risk species.

“Biodiversity Data Journal provides a great venue to share this type of information with our colleagues for regional, national, and international efforts for species conservation,” they note.

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Original source:

Sheffield C, Heron J (2018) A new western Canadian record of Epeoloides pilosulus (Cresson), with discussion of ecological associations, distribution and conservation status in Canada. Biodiversity Data Journal 6: e22837. https://doi.org/10.3897/BDJ.6.e22837

One species described multiple times: How taxonomists contribute to biodiversity discovery

While working on a rare little known group of Oriental wasps that most likely parasitise the eggs of grasshoppers, locusts or crickets, not only did a team of four entomologists discover four previously unknown species, but they also found that another four species within the same genus (Habroteleia) were in fact all one and the same – a fifth species discovered more than a century ago.

Their study, published in the open access journal Zookeys, comes as a fine example illustrating the important role played by taxonomists in puzzling out the Earth’s biodiversity.

The research was conducted by doctorate candidate Huayan Chen and Dr. Norman F. Johnson, both affiliated with The Ohio State University, USA, Dr. Elijah J. Talamas, Florida Department of Agriculture and Consumer Services, USA, and Dr. Lubomír Masner, Agriculture and Agri-Food Canada.

Prior to their study, there were only nine species known in the genus that had been described over the last 113 years from India, Japan and the Philippines.

However, following careful analyses, most of those species turned out to be synonyms of another one discovered in distant 1905, H. flavipes. Because of this species having been described and named five times in total through the years, the richness of the genus has been greatly inflated.

In their turn, having identified four new species belonging to the same genus after studying additional material collected from Madagascar, Papua New Guinea, and the Fijian archipelago, the scientists have maintained the species number in the group intact.

Additionally, the team provides a detailed illustrated identification key to all members of the genus in their paper. This list of characteristic features is set to prevent similar taxonomic confusion in the future.

In conclusion, Chen and colleagues have significantly advanced our understanding of the diversity and biogeography of the rare parasitoids, amongst which there might be some that will eventually prove to be helpful in pest management.

“Taxonomic revisions are essential for the fundamental understanding of biodiversity and its conservation. Taxonomists play a critical role in this process,” explains the lead author.

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Original source:

Chen H-y, Talamas EJ, Masner L, Johnson NF (2018) Revision of the world species of the genus Habroteleia Kieffer (Hymenoptera, Platygastridae, Scelioninae). ZooKeys 730: 87-122. https://doi.org/10.3897/zookeys.730.21846

New parasitoid wasp likely uses unique saw-like spines to break out of its host body

About the size of a sesame seed, a new species of wasp from Costa Rica, named Dendrocerus scutellaris, has elaborate branched antennae that could be used for finding mates. Or hosts.

The new insect is described by PhD candidate Carolyn Trietsch, Dr. István Mikó and Dr. Andrew Deans of the Frost Entomological Museum at Penn State, USA, together with Dr. David Notton of the Natural History Museum in London, UK. Their study is published in the open access Biodiversity Data Journal.

The wasp is a parasitoid, meaning that its larvae feed on a live host insect. There are two types of parasitoids: ectoparasitoids, which lay their eggs on or near the host, so that the hatchling larvae can attach to and feed on the insect from the outside; and endoparasitoids, which lay their eggs directly inside the host, so that the larvae can eat them from the inside out.

Unfortunately, to puzzle out the new wasp’s lifestyle, the researchers could only rely on specimens collected back in 1985, which had spent the past few decades stored in the collections of the Natural History Museum of London before being loaned to the Frost Museum at Penn State for research.

What can you learn about a wasp’s lifestyle from specimens that are over 30 years old? Even though the new species has never been observed in the wild, researchers managed to learn a lot by looking at the wasps’ morphology, concluding that the species is likely an endoparasitoid.

The larva of an endoparasitoid wasp needs a safe place to develop and mature, so when it is done feeding on its host, it may stay inside the host’s body where it can develop undisturbed. Once it is fully grown, the adult wasp either chews or pushes its way out, killing the host if it isn’t already dead.

Unlike its close relatives, the new species does not have pointed mandibles for chewing. Instead, it has a series of spines along its back. While the wasp is emerging, it may rub these spines against the host and use them like a saw to cut open the body. Once emerged, it flies off to mate and continue the cycle.

“While their lives may sound gruesome, parasitoid wasps are harmless to humans and can even be helpful,” explain the scientists. “Depending on the host they parasitize, parasitoids can benefit agriculture by controlling pest insects like aphids that damage crops.”

It is currently unknown what the new species feeds upon, but naming the species and bringing it to attention is the first step in learning more about it.

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Original source:

Trietsch C, Mikó I, Notton D, Deans A (2018) Unique extrication structure in a new megaspilid, Dendrocerus scutellaris Trietsch & Mikó (Hymenoptera: Megaspilidae). Biodiversity Data Journal 6: e22676. https://doi.org/10.3897/BDJ.6.e22676

A race against pine: Wood-boring wasp in North America threatened by a Eurasian invader

Invasive species have diverse impacts in different locations, including biodiversity loss, as a result of native species being outcompeted for similar resources. A U.S. research team, led by Dr. Ann Hajek, Cornell University, studied the case of an aggressive Eurasian woodwasp that has recently established in North America and poses a threat to a native species. Their study is published in the open-access journal NeoBiota.

Most woodwasps play an essential part in the forest ecosystem, as they decompose wood, preferring dying or felled trees. They do so by laying their eggs in the wood underneath the tree bark. Curiously, the wasps also deposit a symbiotic fungus and venom that shuts down the tree’s defenses. As the tree weakens, the fungal infestation begins and the the tree starts to rot. When the eggs hatch, the larvae feed on the rotten wood before they emerge. This relationship is called obligate since the survival of the wasp is impossible without the fungal infestation.

Originating from Eurasia, the presence of the invasive species is dangerous because it can kill healthier pines. It has long been established in the southern hemisphere causing economic issues due to its attacks on pines. While pines have been introduced to that part of the world, they are native to North America, where the invasive wasp could be far more devastating.

Now that the invasive woodwasp has already been identified in the States, the scientists seek to find a way to protect its frail competitor, reporting a rapid decline in the North American species.

“We would often observe both species emerging from the same infested pine trees, but the ratios changed with time,” explains Dr. Ann Hajek.

“Shortly after the invasive colonizes an area, the native wasps emerging from the trees would equal the invasive. However, a few years later, the natives started to get fewer and fewer.”

It turned out that the Eurasian woodwasp has larger venom glands and produces more eggs, thanks to its greater body size. Furthermore, it emerges earlier than the North American species, so that it can find and colonize the most suitable trees first. By the time the native species lays its eggs, the authors speculate, most of the preferred trees are already occupied by the invasive, leaving a reduced supply of habitat for the newcomer’s larvae.

“Woodwasps are difficult to study and their biologies are generally poorly understood,” note the authors. “While the native species appears to be outcompeted from pines that both species prefer, it is possible that populations of the native can be sustained in trees less desirable to the invasive or unavailable during the time and place that the invasive is present.”

The scientists call for additional research on the native woodwasp in southeastern pine forests in USA, before the invaders spread to that area with extensive pine forests.

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Original source:

Hajek AE, Henry JC, Standley CR, Foelker CJ (2017) Comparing functional traits and abundance of invasive versus native woodwasps. NeoBiota 36: 39-55. https://doi.org/10.3897/neobiota.36.14953

A genus of European paper wasps revised for the first time using integrative taxonomy

The European and Mediterranean species of the paper wasp genus Polistes were recently revised by scientists at the SNSB-Zoologische Staatssammlung München (ZSM).

For the first time for this group scientists applied an integrative taxonomic approach which combines traditional morphological methods with modern DNA barcoding.

As a result, the researchers were able to identify a new species from Morocco. For this well-researched wasp group, this is an actual sensation.

The study is published in the open access journal ZooKeys.

The Munich researchers analysed more than 260 wasp specimens collected from across the study area with the help of DNA barcoding.

They managed to identify all species and determine their distribution. In addition, based on the genetic data, they were able to evaluate morphological characters for each species and created a completely new key for identification.

The wasps of the genus Polistes belong to the family Vespidae. The genus is represented by 17 species in Europe and the Mediterranean, with four species occurring in Germany. Within the genus, 13 species are social, with the queen overwintering and founding a new nest with up to 200 workers. Four species are parasitic and have no workers.

Although Polistes has been well-known in Central Europe for more than 200 years, knowledge of Mediterranean species has so far been scarce. Many species of the genus exhibit only subtle morphological differences and show high levels of colour variation, further complicating their identification.

An important result of this research is the separation of species of the Polistes gallicus species complex into three distinct species. Moreover, the genetic data led to the discovery of a new species, represented by a single specimen from the High Atlas Mountains in Morocco. This was an unexpected result for the researchers. The species was named Polistes maroccanus.

Another very surprising result was the discovery of high levels of genetic variation within Polistes dominula, a species commonly found in Central Europe, indicating the presence of up to three different and hitherto unrecognized species – a case requiring further investigation.

Integrative taxonomy is an approach that combines different scientific methods to reliably differentiate species. In particular, DNA barcoding has proven to be a useful technique for the identification of species and for the discovery of new species. The method allows to identify most species quickly and accurately, even those species that are difficult to identify using traditional methods based on morphological characters.

DNA barcoding uses a short gene fragment that differs in almost all species worldwide. The sequences are stored in an online database and can be used for identification. The method derives its name for being reminiscent of the barcodes similar to those found on products in supermarkets that allow quick and error-free identification at the checkout.

DNA barcoding is part of a global research initiative led by the Canadian scientist Paul Hebert from the University of Guelph. The ZSM is a project partner and involved in assembling DNA barcodes of the German animal species. In addition to ZSM researchers, scientists from Switzerland and the Netherlands contributed to the Polistes project.

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Original source:

Schmid-Egger C, van Achterberg K, Neumeyer R, Morinière J, Schmidt S (2017) Revision of the West Palaearctic Polistes Latreille, with the descriptions of two species – an integrative approach using morphology and DNA barcodes (Hymenoptera, Vespidae). ZooKeys 713: 53-112. https://doi.org/10.3897/zookeys.713.11335

Heat-loving Australian ants believe in diversity, hint 74 species new to science

The ‘furnace ants’ or ‘honeypot ants’ present a very large genus of ants, Melophorus, confined to Australia. Long believed to be megadiverse, some scientists have even suggested that the group may contain ‘well over 1000 species’. However, to this point, only 32 species and subspecies had been described.

Scientists Dr Brian Heterick of Curtin University, Dr Mark Castalanelli of Ecodiagnostics Pty Ltd and Dr Steve Shattuck of the Australian National University, funded by an internationally competitive Australian Biological Resources (ABRS) grant, set out to find the true facts.

As a result, they discovered as many as 74 new species belonging to Melophorus. In their study, published in the open access journal ZooKeys, they also provide a taxonomic key to the workers of a total of 93 species in the genus.

Among the studied ants, there are quite bizarre ones, including a species (Melophorus hirsutus) whose eyes are strangely protruding out of his head to a varying degree. In the extreme cases, the eyes are so pointy that could be likened to ice-cream cones. Named many years ago, this ant appears to be older than the rest of the examined living species. Furthermore, unlike most of them, it does not seem adapted to heat. It is confined to the wet eastern coast of Australia.

Dr Heterick spent two weeks collecting specimens in the often rugged and forbidding terrain of Western Australia, while the team also asked a number of major museum collections to loan them specimens.

The newly collected ants were placed in alcohol and subjected to genetic tests using one mitochondrial and four nuclear genes. The findings were then compared with those from physical examinations to prepare the taxonomic key – a set of distinctive features per species that can be used to differentiate within the group.

Given the generally complex nature of these ants, the authors expect for the genus to further expand in future. They speculate that even though the numbers may increase to around 100 species, not the ‘well over 1000’ previously predicted, they still illustrate an incredible diversity.

The authors estimate that Melophorus arose around 35 million years ago. The closest relatives of the genus are also confined to the Australasian region with the exception of a single genus living in South America.

Furthermore, the genus is also quite astonishing thanks to another trait shared among the species.

“By the way, this group of ants has a thing or two to tell those of us who get lost easily!” comments lead author Dr Brian Heterick.

“They can find their way home in a featureless landscape by means of an internal compass influenced by information gathered on earlier journeys. We are not the first species to use a computing system!”

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Original source:

Heterick B, Castalanelli M, Shattuck S (2017) Revision of the ant genus Melophorus (Hymenoptera, Formicidae). ZooKeys 700: 1-420. https://doi.org/10.3897/zookeys.700.11784

3D avatars for three new rare ant species from Africa including the Obama ant

Three new, rare ant species recently discovered in Africa were named after important figures for the African biodiversity conservation – the former United States president Barack Obama, the Nigerian writer and environmental activist Ken Saro-Wiwa, and the world-renowned biologist Edward O. Wilson.

The scientists from the Okinawa Institute of Science and Technology Graduate University (OIST), who had their discovery published in the open access journal ZooKeys, used a new, revolutionary method to compile scans of the ants and create 3D avatars allowing for a unique and detailed visualisation of the insects’ insides.

https://skfb.ly/6sPvr

Curiously, the Obama ant, Zasphinctus obamai, was collected from the Kakamega Forest National Park, Kenya, located near Barack Obama’s ancestral family village. The 44th President of the United States of America is famous for his numerous initiatives towards the conservation of fragile natural habitats around the globe.

Ken Saro-Wiwa, who also has his name perpetualised in the new ant species Zasphinctus sarowiwai, was a Nigerian writer and environmental activist who, after campaigning against irresponsible oil development, was executed in 1995.

“By naming a species from threatened rainforest habitats after him, we want to acknowledge his environmental legacy and draw attention to the often-problematic conservation situation in most Afrotropical rainforests,” explain the biologists in their paper.

The third new species, Zasphinctus wilsoni, bares the name of the biologist Edward O. Wilson, whose foundation has contributed greatly to the resurrection of the Gorongosa National Park in Mozambique.

The 3D avatars were created with the help of X-ray microtomography, or micro-CT, which is a technology similar to the one used in hospitals for CT scans, but relying on much higher resolution. The three-dimensional reconstructions made it possible for the scientists to look into details as tiny as the ants’ mouthparts and even their legs and hairs. Moreover, this method does not require damaging the rare specimens.

“We saw things that nobody ever looked at,” says Dr. Hita Garcia, first author on the study and a member of the Biodiversity and Biocomplexity Unit at OIST.

While closely related ants had already been known as predators of other ant species, the scientists needed to study the data provided by the scans to confirm that the new species are top predators as well.

“Normally when you describe a new species, you don’t know much about its biology,” further explains Dr. Hita Garcia, “but with the 3D reconstructions researchers can discover details right away.”

To the biologists, these reconstructions hint at a future of virtual taxonomy with the potential to alleviate issues of time, money, and specimen damage.

Furthermore, the 3D models also allow for the data to be easily accessible from anywhere. To show this, the scientists have uploaded the reconstructions to the open access Dryad Digital Repository.

“If someone wants to see the Obama ant, they can download it, look at it, and 3D print it,” Dr. Hita Garcia points out.

“Since these ants are from very threatened habitats in Africa, we wanted to pick names that draw attention to the environment, and not just the ants,” he concludes. “The rainforests in equatorial Africa, as well as the savannah in Mozambique, needs to be protected before the habitats and animals living within them are destroyed.”

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Find the original public announcement available via the OIST’s website: https://www.oist.jp/news-center/news/2017/8/29/say-hello-3d-obama-ant

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Reference:

Hita Garcia F, Fischer G, Liu C, Audisio TL, Economo EP (2017) Next-generation morphological character discovery and evaluation: an X-ray micro-CT enhanced revision of the ant genus Zasphinctus Wheeler (Hymenoptera, Formicidae, Dorylinae) in the Afrotropics. ZooKeys 693: 33-93. https://doi.org/10.3897/zookeys.693.13012

The ‘Star dust’ wasp is a new extinct species named after David Bowie’s alter ego

During her study on fossil insects of the order Hymenoptera at China’s Capitol Normal University, student Longfeng Li visited the Smithsonian National Museum of Natural History, Washington, carrying two unidentified wasp specimens that were exceptionally well-preserved in Burmese amber. This type of fossilized tree resin is known for the quality of the fossil specimens which can be preserved inside it. Being 100 million years old, they provide an incredible view into the past.

The subsequent analysis of the specimens revealed that both represent species new to science. Furthermore, one of the wasps showed such amazing similarities to a modern group of wasps that it was placed in a currently existing genus, Archaeoteleiawhich has long been considered as an ancient lineage. The species are described in a study published in the open access Journal of Hymenoptera Research.

However, Archaeoteleia has changed since the times when the ancient wasp got stuck on fresh tree resin. The authors note that “a novice might not recognize the characters that unite the fossil with extant species”. For instance, the modern wasp species of the genus show visibly longer antennal segments and a different number of teeth on the mandible when compared to the fossil. In turn, the description of the new extinct species enhances the knowledge about living species by highlighting anatomical structures shared by all species within the genus.

This fossil wasp with living relatives received quite a curious name, Archaeoteleia astropulvis. The species name, astropulvis, translates from Latin to ‘star dust’. The discoverers chose the name to refer to both “the ancient source of the atoms that form our planet and its inhabitants”, as well as to commemorate the late David Bowie’s alter ego – Ziggy Stardust.

Unlike the Star dust wasp, the second new species belongs to a genus (Proteroscelio) known exclusively from Cretaceous fossils. Likewise, it is a tiny insect, measuring less than 2mm in length. It also plays an important role in taxonomy by expanding the anatomical diversity known from this extinct genus.

The authors conclude that their discovery, especially the Star dust wasp and its placement in an extant genus, where it is the only fossil species, “exemplifies the importance of understanding the extant fauna of a taxon to interpret fossils”.

“Such union of fossil and extant morphologies is especially illuminating and requires examination of both kinds of specimens,” they add.

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Original source:

Talamas EJ, Johnson NF, Buffington ML, Dong R (2016) Archaeoteleia Masner in the Cretaceous and a new species of Proteroscelio Brues (Hymenoptera, Platygastroidea). In: Talamas EJ, Buffington ML (Eds) Advances in the Systematics of Platygastroidea. Journal of Hymenoptera Research 56: 241-261. https://doi.org/10.3897/jhr.56.10388

The Radiohead ant: A new species of ‘silky’ ant grows fungus gardens for food

The ants of the genus Sericomyrmex – literally translated as ‘silky ants’ – belong to the fungus-farming ants, a group of ants that have figured out how to farm their own food. The silky ants are the less well-known relatives of the famous leaf-cutter ants – well-studied, photogenic model organisms that you simply cannot avoid if you take a trip to the Neotropics.

For their study, now published in ZooKeys, Ana Ješovnik and Ted R. Schultz from the Smithsonian Institution‘s Ant Lab in Washington, D.C., collected silky ants from across their entire range in Central and South America, and revised the genus based on DNA sequence data and morphology. In the end, they turned out to have discovered three new species.

One of those species, Sericomyrmex radioheadi, collected in the Venezuelan Amazon, was named after the famous British music band Radiohead.

“We wanted to honor their music” one of the authors, Ana Ješovnik, says. “But more importantly, we wanted to acknowledge the conservation efforts of the band members, especially in raising climate-change awareness. ”

Using a scanning electron microscope, the authors found that the bodies of the ants are covered with a white, crystal-like layer. Curiously, this previously unknown layer is present in female ants (both workers and queens), but is entirely absent in males. Both the chemical composition and the function of this layer are unclear.

One possibility is that the layer is microbial in origin and that it has a role in protecting the ants and their gardens from parasites. This is interesting, because most of the fungus-farming ants cultivate antibiotic-producing bacteria on their bodies to protect their gardens from microbial weeds. In the meantime, in Sericomyrmex these bacteria are absent, yet their gardens are also parasite-free. Figuring out if this crystal-like layer has a role in protecting these ants’ fungus gardens might provide clues for managing diseases in human agriculture and medicine.

At only four million years, Sericomyrmex is an evolutionary youngster, the most recently evolved genus of fungus-farming ants, and an example of rapid radiation – comparable to other fast-evolving groups, such as the freshwater fishes in Africa, or the Hawaiian fruit flies.

Rapid radiation is a process in which organisms diversify quickly into a multitude of forms, making these ants good candidates for studies into speciation and evolution. In the present article, the authors acknowledge that some of the species they describe might, in fact, be multiple species that look alike, but because the ants are in the early stages of speciation, this is hard to detect.

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Original source:

Ješovnik A, Schultz TR (2017) Revision of the fungus-farming ant genus Sericomyrmex Mayr(Hymenoptera, Formicidae, Myrmicinae). ZooKeys 670: 1-109. https://doi.org/10.3897/zookeys.670.11839